Fluid Mechanics Ideal Flow Problem

AI Thread Summary
The discussion revolves around calculating flow velocity and magnitude at a specific point in a fluid mechanics problem involving a sink, vortex, and uniform flow. The user initially struggles with their calculations, resulting in incorrect values for velocity components and overall flow. After reevaluating the problem and focusing on the necessary units, they successfully arrive at the correct solution. The final values achieved are V = 12.5 m/s, u = 10 m/s, and v = 7.5 m/s, with an angle of α = 37 degrees. The user emphasizes the importance of simplifying the approach to solve the problem effectively.
Wildcat04
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Homework Statement



Calculate flow velocity and magnitude at a point (2,-2)

Sink at origin with strength 20 m2/s
Vortex at (0,2) with strength 25 m2/s
Uniform flow in +x with strength of 10 m/s

The Attempt at a Solution



\phi = \phi1 + \phi2 + \phi3

\phi1 = -Ux = -U r cos(\theta)
\phi2 = -\mus ln r
\phi3 = \muv \theta

vr = d\phi/dr
=-U * cos \theta - \mus * (1/r)
=-10 cos(\pi/4) - 20 / 2.83
=-14.14

v\phi = (1/r) d\phi / dr
= (1/r) (-14.14)
= -5

u = .5 (14.14) + .5(5) = -9.57
v = -.5(14.14) + .5(5) = 4.57


I know that I have butchered this because the solutions is supposed to be

V = 12.5 m/s
u = 10 m/s
v = 7.5 m/s
\alpha = 37 degrees

Could someone please point out the obvious flaw in my logic and point me in the right direction?

Thank you very much in advance!
 
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Nevermind! I was making this problem a lot harder than I thought it was. I took a step back and looked at the units that I needed for my solution along with what the correct solution and was able to work it out.
 
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